Hawaiʻi is said to have been named for Hawaiʻiloa, the legendary Polynesian navigator who first discovered it. Captain James Cook, the European who claimed to have discovered the Hawaiian Islands and called them the "Sandwich Islands", was killed on the Big Island at Kealakekua Bay.
Hawaiʻi was the home island of Paiʻea Kamehameha, later known as Kamehameha the Great. Kamehameha united most of the Hawaiian islands under his rule in 1795, after several years of war, and gave the kingdom and the island chain the name of his native island.

The Island of Hawaiʻi is built from five separate shield volcanoes that erupted somewhat sequentially, one overlapping the other. These are (from oldest to youngest):
* Kohala—extinct
* Mauna Kea—dormant
* Hualālai—active but not currently erupting (dormant)
* Mauna Loa—active, partly within Hawaiʻi Volcanoes National Park
* Kīlauea—active: has been erupting continuously since 1983; part of Hawaiʻi Volcanoes National Park

About 35 km (22 mi) southeast of Hawaii lies the undersea volcano known as Loihi. Loihi is an erupting seamount that now reaches about 3,200 feet (980 m) below the surface of the ocean. Continued activity from Loihi will likely cause it to break the surface of the ocean sometime from 10,000 to 100,000 years from now.
--- http://en.wikipedia.org/wiki/Hawaii_(island)